Perforator



Jan. 18,1927. 1,615,172

D. W. HOFERER I PERFORATOR Filed June 16, 1924 2 Sheets-Sheet I WXM D. w. HOFERER PERFORATOH Jan. 18, 1927. l 1,615,172

Patented Jan. 18, 1927.

i UNITED STATES PATENT OFFICE.

DANIEL W. HOFERER, OF WHITTIER, CALIFORNIA, ASSIGNOR TO JOY J. RICHART. OF

WHITTIER, (LAIZIIISORNIA.

PERFORATOR.

Application filed .Tune 16, 1924. Serial No. 720,282.

This invention relates to a perforator, and has particular reference to a device for perforating pipe or casing in a well, or the like.

j, ln the construction of a well, Such as an oil weil, it is the common practice to encase the walls of the well with acasing leading down to the formation from which the oil is to be produced. The lower end of this casing may be provided with a `screen section is to enter the well. In other cases, the lower end of the casing may be perforated after the casing is placed in the well in order to provide suitable screening openings for admission of the oil into the Well. It frequently occurs that after the casing has been installed in a well, it is found that the first screen section o1' perforated section of the casing is improperly positioned so that the oil from the formation does not enter the well. In this case, it is necessary to perforate or form screening openings in `the casing at a different position in order to permit ingress of the oil from the formation into the well bore. Moreover, frequently in the drilling of oil wells, a plurality of oil producing sands or formations will be enc-ountered and it may be desirable to drill beyond the first oil producing formation into. a lower producing formation to extract the oil iii-st from the lower section. In this case, after the production from the 'lower formation has declined, it laterbecomes desirable lo establish conununication between the up- -3 per producing formation and the well bore.

In such a case, itis necessary to provide suitable means by which the casing can be perforated at th'e desired points. Moreover, due to the various causes encountered in drilling or constructinga well, the producing formation may be shut off from the interior of the well bore by a plurality of strings of well casing. This happens when, for example, one well casing becomes stuck in the well f bore or it is necessary to cement a string of easing in the well bore to shut off water and then later a second and smaller string is positioned within the well hole to permit extension of the well bore. IVherever the further drilling of the hole through such second casing establishes that it is desirable to back up and attempt production through points in the Well above the bottom of the outer string, we have a condition where the i through which the oil from the formation Well bore is shut olf from the formation by two Separate casings.

Heretofore, the art has been provided with no satisfactory practical means by which -communicationcould be had between a well well bore and perforate through a plurality of casings which enclose the well bore from communication with the adjacent formation.

When it is desired to perforate through more than a single casino if. is necessary to provide a cutting tool havintr an exceptionally long blade which must in the operation of perforating a plurality of strings, project a very substantial distance from the exterior surface of the well perforating tool. Moreover, in order to permit the passage of such perforating tool through the well bore, in positioning the tool opposite the point to be perforated and in removing the tool after the perforating operation, it is necessary that this long cutting blade should be properly housed within the perforator body. Due to the length of suc-ha cutting blade, it is therefore necessary that -it lie in the body substantially longitudinally to the axis ot' the body. Therefore, when the cutting blade is moved to project from the body sufficiently to first engage the inner' surface of the inner casing, it is at a very slight angle with the casing surface and the engagement between the casing surface and cutting blade is not suflicient to force the long cutting blade into a cutting position o r to perforate through the easing.4 For this reason, the prior perforating tools have beenl confined to devices employing short cutting blades or points which were adapted only to perforate a single casing.

I have discovered that by the provision in a perforating tool of a cutter provided with a plurality of cutting blades rigidly attached together and forming part of one pivotally mounted cutting member, and by forming one of these blades of short length and arranged to lie at a different angle relalength to perfor'ate two casings, the shorter blade may be brought into position with the inner casing in such position as to cut into the casing sufficiently to form a positive le-` verage point which will force the other longer blade into the casing to perforate the same despite the slight angle of original approach of such longer cutter.

Other features of the invention include the provision of means for initially advancing at will the cutter of the perforator to position first only the shorter blade of the cutter in position to engage with the casing of the Well, which means are operative from the top of the well, as desired.

lThe various objects and features of this invention will be best and more fully understood from the following detailed description of a typical preferred Vform of the invention throughout which description reference is had to the accompanying drawings in which Fig. 1 is a side elevation of the perforator provided by this invention showing it completely collapsed or unactuated.

Fig. 2 is a vertical detailed sectional view of the perforator showing it unaetuated.

Fig. 3 lis a view similar to Fig. 2 showing the perforator partially actuated.

Fig. 4 is a sideelevation of the perforator, being a view taken as indicated by line 4-4on Fig. 2.

Fig. 5 is a vertical detailed sectional view ofthe perforator being a view taken as indicated by line 5-5 on Fig. 2. l

Fig. 6 is a detailed transverse sectional view of the perforator taken as indicated by line 6--6 on Fig. 2. i

Fig. 7 is a detailed transverse Isectional view of the perforator taken as indicated by line 7-7 on Fig. 2.

Fig. 8 is a detailed transverse sectional view of the perforator taken as indicated by line 8;-8 on Fig. 2. f

Fig. 9 is a detailed transverse sectional view of the perforator taken as indicated by line 9 9 on Fig.l2.

Fig. 10 is a detailed transverse sectional view of the perforator taken as indicated by line 10-10 on Fig. 2, and

`Fig. 11 is a detailed sectional view taken as indicated by line 11-11 on Fig. 7.

The device providediby this invention is intended primarily for use in perforatging casings, o-r the like, 'in a well. The invention is of particular value in perforating a doubly-encased well hole. By a doubly-encased well hole is meant a well hole in which there i are two metallic casings telescoped one over the other or a well hole in which there is mg to beperforated and 'may be provided at its upper end with 'a tapered screw threaded projection or pin 13 by which it may be connected with a suitable operating means.,

for instance, a string of drill pipe,- 4 y The body 10 forms a frame vor'cari" 'Y "(1 the other parts ot' the device, andishprovitlcd with an opening 14`for the reception jlor-tli'e other parts. 1n accordance with the .preferred form of the invention the opening ll.- is in the form of a groove in one side ot the body and extends longitudinally of the body as clearly shown in Fig. 4 of the drawings. The groove 14 starts at the-lower end of the bodyv and extends upwardly in the body a considerable distance. The groove is comparatively narrow and deep and has sockets 15v at opposite points in its side and walls 16 near it-s upper end. The sockets l5 are round and are formed in the sides 16 ad- ]acent the bottom 17 of the groove. Ret-esse.;

4 18 are formed at opposite points in the sides 16 immediately beyond for instance above the sockets 15. The recesses extend inwardlyY from the top or outer partl ot' the groove and communicate with or join the sockets 15 in the' manner clearly illustrated in Fig. 11 of the drawings. The inner or bottom portion of the groove is enlarged for a considerable distance upwardly from the lower end of the body. The enlarged part-19 may be formed by cutting away the sides of the groove, for instance, by boring from the lower end of the body, and'isv terminated at its upper end by downwardly` facing shoulders 20.

The cutter'll is carried by the opening in the body so that itis movable from a position where'vit is completely in the body and has no part projecting or protruding trom the body to a. position where it has partal pro jecting a substantial distance from one .side to the body. The mainportion or shank 2l of the cutter slidably fits between the sides 16 of the groove 14\and is provided at its inner end with trunnions 22, whichsupport the cutter for movements in a plane longi-l tudinally of the casing being perforated. The trunnions 22 extend from opposite sides of the cutter and are adapted to fit or be carried in the sockets 15 in the walls of the groove 14. The trunnions are preferably solid or integral with the shank ot the cnttei-.and are adapted to be arranged in and removed from the sockets 15 through re-v cesses 18. The trunnions 22 are retained in the sockets 15 by retaining block-s 24 arranged in the recesses 18 to extend inwar,dly.l30

over the trunnions in the manner clearly illustrated in Fig. 11 of the drawings. The retaining blocks 24 are preferably made to .completely till ythe recesses 18 and are secured 1n place by suitable means, say for instance, by means of screws 25 which extend into them from the exterior of the body 10, as clearly illustrated in Figs. 5, and 6 of the drawings.

When the cutter 11 is in its normal or unactuated position its main portion or shank 21 hangs downwardly in the groove 14 in the body and no part of the cutter projects or protrudes from the body. In the case of a tool for operating on the plurality, say two, casings at a time, the cutter is provided at lts outer part with two cutting parts and 31. The cutting parts are formed directly on the outer part of the shank of the cutter and are of different lengths; the short cutting part 30 being adapted to engage and cut through the innermost casing indicated at A in Fig. 3 and the long cutting part 31 being adapted to extend through the inner casing A and through the outer casing B. The two-cutting parts 30 and 31 extend in different directions with reference to the pivotal axis of the cutter. The short cutting part 30 is at the upward or leading portions of the shank so that it is the first to project from the body 10 when the device is operated. In practice, the cutter is designed and proportioned so that the short cutting part 3() engages or operates on the inner casing A before the long cutting part engages the inner casing. In Fig. 3 of the drawings, I have illustrated the cutter partially actuated in which position the short cutting part is operating upon the inner casing A while the long cutting part is just coming into engagement with lthe casing A. It will be obvious, of course, that thecutting parts may in practice be'varied in size, shape and arrangement depending upon the character of perforators desired, the casings to be perforated, etc. A

The cutter actuating means 12 provided by the present invention to actuate the cutter 11, includes, generally, a wedge 40 slidably carried in the groove 14 in thebody 10, a tail piece or other suitable devices 41 located below the lower end of the body 10, and a tail rod 42 connecting the tail piece and wedge. The wedge 40 may be in the form of a block slidably fitting the groove 14. The wedge is provided atopposite sides with projections 43 which extendinto the enlarged portion 19. The projections have flat upper ends 44 forming shoulders adapted to engage and cooperate with the shoulders 20 at the upper ends of the enlargement 19. The .upper part or end of the wedge 40 has an upwardly and inwardly inclined wedge face 46 adapted to'cooperate with the cutter to move or force it out when the wedge is moved upwardly. The parts are arranged and proportioned so that the wedge upon being moved upwardly engages behind the long cutting part 31 and forces or swingsthe cutter outwardly in the direction indicated by the arrow C in Fig. 3 to or beyond a position where the short cutting part 3() has engaged or entered the inner casing A. The projections 43 in the wedge are made to more or less accurately fit the enlargement 19 in the groove so that they operate to guide the wedge in its Inovement. Further the enlargen'lent 19 and the projections 14 are proportioned and related so that the shoulders 20 and 44 cooperate to si.

limit the upward movement of the wedge so that the wedge cannot be forced too far upwardly and cannot injure the cutter.

The tail piece 41 may, as far as the present invention is concerned, be any suitable dei.;

the casing. The tail rod 42 is preferably a 1i' plain rod having its upper end fixed to the wedge 40 and its lower endconnected to the tail piece 41.

A block 50 is preferably arranged in the lower end of the groove 14 to guide the tail 42 and to form a stop for the downward .movement of the wedge so that the wedge will not become displaced from the body. The block 50 may be secured in place by means of screws 51 so that it can be readily removed if necessary.

It is desirable to limit the upward swinging movement of the cutter 1l, for instaure. by means of a suitable shoulder (3() in the groove 14 to cooperate with or be engaged by theA shank of the cutter. In the preferred arrangement the stop shoulder (50 is formed on a block 61 adapted tov be arranged in the upper end in the groove 14 in -the manner clearly shown in Figures 2, 3 and 5 of the drawings.y The block G1 may be retained in place by means of a suitable pin 62.

In operation the device is lowered into the inner casing A on the end of a suitable operating member, for instance, a string of drill pipe. At the desired point 1n the casing A the tail piece is tripped or 'z-.ctuaterh the particular operation manipulated necesset forth but wish to reserve to myself any- `short cutting part 30 with lthe casing A causes the cutter to continue to operate in the direction indicated by the arrow C in Fig. 3 so that the long cutting part '31 passes outwardly through the casing A and through the caslng B.V W'hen this operation is completed the device is returned to its normal position by upward movement of the body 10. v

Having described only a typical preferred form of my invention I do not wish to limit myself to the specific details hereinabove changes or variations that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my present invention, I claim- 1. A casingl perforator including, a body, a cutter pivotally carried bythe body, the cutter -having cutting parts of different lengths and being movable in a-plane longitudinally of the'casing being erforated between a position where it is vwlthin the body and a position where its cutting parts'project from the body, and means for actuating the cutter. f l

2. A casing perforator including, a body, and a cutter carried by the body, the cutter having two cutting parts of different lengths and being movable in a plane longitudinally of the casing being yperforated between a position where it is within the body and a position where its cutting parts project from the body, the cutting parts being related so that the short cuttlng part is the first to project from the body when the cutter 1s actuated.

3. A casing perforator including, a body, and a cutter carried by the body, thecutter having two cutting parts of different lengths and being operable in a plane longitudinally of the casing being perforated and from a position where the cutting parts are within the body to a position where they project from the bdy, the cutting parts being related so that the short one is first to project from the body when the cutter is actuated, and means for pozitively actuating the cutter until the short cutting part projects from the body. 4:. A casing perforator including a body having a groove, there being sockets at opposite points in the sides o f the groove,

there being recesses at opposite points in the sides of the groove communicating with the 'socket, a cutter, trunnions extending from opposite sides of the cutter and adapted to be arranged 'in the sockets through the recesses, the cutter being operable in /a plane longitudinally of the casing being perforated, and means for closing the recesses.

5. A casing perforator including a bodyl Y rece3ses, blocks adapted to be arranged in the recesses to retain the trunnions in the sockets, an enlarged portion in the lower' end of the groove terminating in a downwardly facing shoulder, a wedge slidably carried in the groove below the cutter to cooperate with the cutter tomove itl to a position where the cutting parts project from the body, aprojection on the wedge operating in said 'enlarged portion and presenting a shoulder to cooperate with said first mentioned shoulder tolimit the upward Amovement of the wedge, a tail rod connected with the wedge and extending downwardly therefromto a point below the.lower end of the body, and a'block arranged at the lower end of the body to guide the tail rod and limit the downward movement of the wedge.

l(i. A casing perforator including a body, a cutter pivotally mounted in said body and including two cutting parts extending radially from the pivotal axis of the cutter, the cutting parts being of different lengths and related so that the shortest one operates before the longest one, said cutter being mounted vfor cutting movement in a plane longitudinally ofthe casing being perforated.

7. A casing perforater including a body,

a cutter including two cutting parts carried by the body operable to project different distances from the body, the cutting parts being related so that the 'cutting part projecting the shorter distance from the body operates first and aids the operation: of the other cutting part, said cutter being mounted for cutting movelnent in a plane longitudinally of the casing being perforated.

8A casingvperforator adapted for forming screening openings in the casings of a doubly encased well hole, comprising a body, a cutter pivotally lcarried by the body, for movement in a plane longitudinally of the casing being perforated, said cutter having blades of different lengths, one adapted to engage the inner casing and operative as a feeding elementfor rotating the cutter to force the other blade into perforating posi tion, the other blade being of a length sufficient tov perforate both casings, the cutting blades being set at an angle one to the other.

9. A casing perforator adapted for forming apertures in the casings of a doubly encased Well hole, comprising a bodyT adapted to be lowered into a Well hole, a cutter carried by the body and movable in a plane longitudinally ot' the casing being perforated tronia closed position within the body to a perfor-ating position troni the force iinparted to the cutter by t-he relative longitudinal motion between the casing and body, the cutter having blades ot' diii'erent lengths,l one adapted to engage the inner casing and operate as a feed elenient :tor rotating the cutter to force the other cutting blade into the perforating position on longitudinal motion of the perforator, the other blade being of a length suiicient to perforate both casings.

10. A, casing perforator adapted for forin-v ing screening openings in the Yeasing-s of a doubly encased well hole., comprising a body lower-able into the well bore, a cutter carried by the body, the critter having blades of diti'erent lengths, one blade being adapted to engage the inner casing and operate as a feeding element for rotating the cutter to force the other blade into the perforating position, such action taking place through a longitudinal motion of thevperforator, the

other blade being of a length suilicient to perforatel through both casings in the perforat-ing position, the cutter being housed in the body in one position so that it is pro tected from engagement With the well casing, and an anchor member carried by the body and operative to engage the casing to initially translate the. cutter into position where the first or shorter cutting blade is in engagement with the Well casing.

ll. In a casing perforator adapted for forming apertures in casings of a doubly encased Well hole, the combination of a body, a cutter carried by the body and provided with cutting blades, one cutting blade being adapted to engage the inner casing to operate as a feeding element for rotating the cutter to force the other blade into the perforating position upon a longitudinal movemeut ot' the body, Said other blade being of i a length suiiicient to extend laterally from the body and perforate both casings in the perfor-atingposition, and al tail anchor slidably secured to the body and providedwit-h a wedge operating to translate the cutter to position in which the shorter cutting blade is in engagement with the Well casing.

In Witness that I claim the foregoing I have hereunto subscribed my name this 10th day vof June 1924.

DANIEL WV. HOFERER. 

